1. Field
Embodiments disclosed herein relate to an automatic analyzer having a mechanism that washes the dispensing probe that dispenses a liquid.
2. Description of the Related Art
An automatic analyzer generates analytical data expressed with a concentration of a test item component in a sample, the activity of enzyme, etc. by measuring optically a change of a color tone and turbidity produced by the reaction of a mixed-liquid of samples, such as a suspected sample extracted from a sample for a biochemistry test item, an immunological test item, etc., with a reagent of each analysis item in a light measurement part of a spectrum photometer or a nephelometry meter.
With this automatic analyzer, an analysis item set up out of two or more analysis items for every suspected sample is analyzed. Further, a photometry unit measures the mixed-liquid of the suspected sample and the reagent suctioned in a reaction cuvette. A sample dispensing probe is washed by a washing tank for every end of the sample dispensing probe. Moreover, a reagent dispensing probe is washed by a washing tank for every end used for reagent dispensing.
In addition, there is a blood collection tube that accommodates the whole blood collected from a subject in the sample container used with the automatic analyzer.
The whole blood accommodated in this blood collection tube is divided into an upper layer sample containing serum or plasma and a lower layer sample containing a blood cell component, etc. Further, the upper layer sample is dispensed and the dispensed sample is analyzed regarding each analysis item. When the upper layer sample is suctioned, the end of the sample dispensing probe may attract a sample in the position where the end part, which has fallen several mm from the surface, and the upper layer sample adheres to the end outside side of the sample dispensing probe. The sample adhering to the sample dispensing probe pollutes the sample in the sample container that is dispensed in the next dispensing. As a method of solving this problem, a washing method that washes the end outside side of a sample dispensing probe has been proposed (for example, see Japanese Patent No. 4175916).
Recently, the lower layer sample in a blood collection tube is dispensed and, for example, an analysis item of glycohemoglobin, etc. is analyzed. In suction of this lower layer sample, for example, in order to pass the upper sample and to attract the lower layer sample that is tens of mm below a surface, the sample adheres to a wide range external surface containing the end part of the sample dispensing probe. When the reaction cuvette is made to flow out the sample obtained after the sample had adhered to this sample dispensing probe external surface, the sample adhered outside falls into the reaction cuvette, and there is a problem in which the dispensing accuracy of the lower layer sample is lower. Moreover, there is a problem that the next dispensed sample in the sample container is polluted by the sample that adheres to the outside of the sample dispensing probe.
If one tries to wash away the sample adhering to the wide range external surface of the sample dispensing probe by the method indicated by U.S. Pat. No. 4,175,916 in order to solve this problem, it is necessary to enlarge the path of the washing tube. Further, in order to prevent spilling of washing water, it is necessary to emit a lot of washing water with a strong pressure. Therefore, it is necessary to enlarge the washing tank to prevent the spilling of washing water.
By the way, a washing method that washes the external surface of a reagent dispensing probe is known (for example, see Japanese patent application publication No. 2002-162403). It is possible using this method to wash the sample dispensing probe. By the washing method indicated by Japanese patent application publication No. 2002-162403, the cleaning liquid spouts so that it will be applied and wash the sample dispensing probe.
However, due to the position where the cleaning liquid is applied, and because it is difficult to make the cleaning liquid cover the whole wide range external surface of the sample dispensing probe, the sample remains on the sample dispensing probe external surface, and there is a problem that the next dispensed sample in the sample container is polluted by the sample that adhered outside of the sample dispensing probe.